Okay I have the monitor!!! I'll try not to be too wordy:
Summary: I love the monitor! I feel some regret it doesn't immediately look as nice as a glossy IPS one would. Recommended upgrade if you are not using a 1440p IPS panel. If you are, well, it is still awesome! Especially in a dark room where the AR coating doesn't affect the image quality as much.
IT JUST WORKS. If you've read any of the reviews of the other 4k monitors, this one is different. Everything just works. 60Hz, responsive, no MST and display port is way better than HDMI (overscan etc.). Plug it in and play. It is perfect with a R9 GPU. I really love the joystick on the back for the menus, and display switching is quick, but don't use non HD sources with it... yuck that looks bad! (no 480p scaler?)
I'm coming from a 40" high-end Samsung TV (PLS?). It was glassy, glossy, 1080p and huge. This has AR (anti reflective coating) and plastic, and it is big enough and attractive enough except for the bezels.
Use Internet Explorer for web browsing! Chrome looks like garbage in comparison.
I used http://jasonfarrell.com/misc/deadpixeltest.php
to check for dead pixels. There are 3 light grey dots, almost unnoticeably tiny on the monitor, visible on the colored backgrounds. Dead pixels?
TN panel. There is no mistaking this is a TN panel, but a good one. I usually have my face close to the screen, so the viewing angle issue is noticeable in windows when moving your head, because the angle from your eyes to the edge of the monitor is already greater than 45 degrees. For example, in Skype when I move my head, the color and brightness of the scroll bars changes a little. If your head is two feet away it looks stunning. If you are peering into it from a short distance it is fine in games, but Windows does look a little off compared to the perfect uniformity with IPS.
Use windows 8 scaling. Everything is not tiny on the screen. It works really well. Actually 1440 looks great for anything, so you don't have to worry about the power of your system and can just use 1440 in the desktop if you need to.
I'm really loving this monitor. The TN issues don't bother me in any games, just in windows. I paid $599 for this, so since a normal 28 inch monitor is about $350, it wasn't that hard to decide that I wanted a 4k one. If you already have an IPS 1440 display, I'd wait for the 4k IPS monitors personally, but then I'm poor. This is a good value and a great upgrade from 1080p, even if it is smaller than a TV (-:
You still need antialiasing to get rid of shimmering even if you can't see the pixels easily, but crap you need a lot of power to use 4xMSAA with 4k. Not possible for me...
I've played StarCraft 2 all morning (-:
Mass Effect 3 runs great too, but at 4k like many games, the UI doesn't scale right, so I'd rather play at 1440 so that the UI is correct.
Really that is the only proviso for me, 1440 is so good already, I'm sure this monitor doesn't make sense for everyone. But in Canada, if you don't order off of eBay from Korea, there are no 1440 screens cheaper than this one, so why not buy the 4k one for the same price? Exactly! (-: